We are investigating the mechanisms whereby steroid and polypeptide hormones stimulate growth and specific protein synthesis in human breast cancer both in tissue culture model systems we have established and in clinical settings. A. We are studying the prevalency and clinical correlates of specific steroid receptors for estrogen, androgen, glucocorticoid and progesterone in human breast cancer, lymphomatous diseases and melanoma. B. Assays for specific gene products (alpha-lactalbumin, CEA, casein, fatty acid synthetase) have been developed and we are studying the effects of steroid hormones and insulin on the activities and synthetic rates of those proteins. C. We are investigating glucocorticoid receptors in various subpopulations of normal and leukemic lymphoid cells including their regulation by mitogenic stimulation by phytohemagglutinin.